Read on to learn exactly what ocean noise pollution is, how it affects marine life, and what we can do to help reduce its impact on the ocean and animals.

Ocean noise pollution is a form of environmental pollution caused by human activities—like commercial shipping, oil exploration, seismic surveys, offshore wind turbine installation, and military sonar—that generate unnatural and excessive sound underwater. For marine mammals in particular, this noise pollution can interfere with and obscure their ability to hear natural sounds in the ocean, which can disrupt their natural behaviours and interfere with their ability to communicate.

Increased background noise in the ocean is a direct result of the upwards of 250,000 vessels travelling across the global ocean at any one time. Cargo ships can emit as much as 190 decibels of noise, which is much louder than a plane taking off and about the same noise level as a rock concert. Noise also travels much faster in water than in air, meaning the increased noise levels affect animals and habitats far and wide.

Marine life is affected by ocean noise pollution in many ways.

Many animals, including dolphins, whales, and fish, use vocalisations to communicate. When consistent unnatural noise masks these calls, it becomes harder for the animals to hear and find each other, coordinate hunts, and detect and warn others about predators.

Ocean noise is especially problematic for animals that rely on echolocation, like dolphins and toothed whales. Excessive noise can disrupt these signals, causing the animal to become disoriented and unable to hunt successfully.

As well as disturbing essential life activities, noise can also indirectly cause injury. Military sonar and seismic air guns are high intensity and excessively loud, and can send animals into a panic. To get away from the noise, they might ascend too quickly, leading to decompression sickness and skin damage from gas bubble lesions. In some cases, loud sounds can cause hearing loss or even cause animals to strand and die.

As ecosystems in the ocean are so complex and interconnected, the direct effects of noise pollution on one species will indirectly affect another. For instance, if a whale strands on a beach in response to sudden, intense noise from a human activity, the whale dies on land instead of at sea, and its body doesn’t sink to the sea floor as it normally would. The seafloor-dwelling animals that rely on the whale’s body for food and sustenance then lose a key food source.